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University of California Publicatioiis in Agricultural Sciences [Vol. 3 



lows : A, 56.9 mg. nitrogen ; B, 46.3 mg. nitrogen ; and C, 38.7 mg. 

 nitrogen. In attempting to correlate the variations in ammonifying 

 powers with the known variations of the soils, or with the known his- 

 tories of the soils, there seem to be no relations of significance. 



The Altamont and Diablo types are about alike in their low am- 

 monifying power. The Hanford and San Joaquin are both higher 

 and nearer to each other than to the two heavy types, yet the Hanford 

 is noticeably higher than the San Joaquin. This is as one would ex- 

 pect, from a knowledge of the soils in the field. Considering the types 

 as a whole, as represented by the A horizon, there are more marked 

 variations between the types than between the samples of a given type 

 though the variations within a given type are very large. 



Table 29 — Ammonification 

 Diablo Clay Adobe 



Milligrams N as NH 3 Produced 



Table 30 — Ammonification 



Altamont Clay Loam 

 Milligrams N as KH 3 Produced 



